Two trucks lie on their sides on a bridge at Toyama city, western Japan on April 3, 2012 (AFP Photo / JiJi Press) / AFP

A powerful rainstorm is battering Japan, paralyzing traffic and leaving thousands of homes without electricity. The storm halted commuter trains and grounded more than 500 domestic flights in and around Tokyo.

Three people have been killed and at least 305 injured by the rainstorm, which lashed Japan's main island of Honshu Tuesday. Public broadcaster NHK tallied at least 97 people injured across 17 prefectures.

As many as 11,500 households have lost power because of the storm in Toyama and Ishikawa prefectures, Hokuriku Electric Power Co. said in a statement. Many companies and stores closed early.

Winds of up to 140 kilometers per hour were nearly typhoon strength, reports Bloomberg, but the storm was triggered by a low pressure system.

"This is like the core of a typhoon, but it is staying for a long time. A typhoon usually moves rather quickly," a spokesman for the Japanese Meteorological Agency said.

The storm has already dumped up to 6 centimeters (2.4 inches) of rain an hour in central Japan as it crossed from the southwest and is heading for the capital city. This is the strongest storm to hit Tokyo since 1959.

Japan's weather agency has issued a warning of possible tornadoes in the western half of the country and said heavy rain could also trigger landslides and flooding. The outlook for Wednesday shows strong winds are likely to move northwards, producing waves up to 10m high.